Although it is the responsibility of the motorist to check before opening their door, riding too close to parked cars (in the door zone) is still a common mistake bicyclists make that can lead to serious injury. For more information on this type of bicycle facility, visit the Sharrows FAQ.
triangle. n. 1. (Mathematics) geometry a three-sided polygon that can be classified by angle, as in an acute triangle, or by side, as in an equilateral triangle. Sum of interior angles: 180Â°; area: base Ã height. 2. any object shaped like a triangle. 3. any situation involving three parties or points of view. See also eternal triangle. 4. (Instruments) music a percussion instrument consisting of a sonorous metal bar bent into a triangular shape, beaten with a metal stick.
Geometric shapes, also called figures, are an important part of the study of geometry. The triangle is one of the basic shapes in geometry. It is the simplest shape within a classification of shapes called polygons. All triangles have three sides and three angles, but they come in many different shapes and sizes.